Intermittently acting rolling mill

ABSTRACT

Intermittently acting rolling mill comprising continuous rotary drive means, a roll cage which is reciprocated longitudinally of the work, means by which said work is intermittently rotated, and means for converting the continuous rotary movement of said drive means to reciprocating movement to drive said cage and intermittent rotary movement to turn said work in synchronism with the movement of said cage.

[151 3,698,225 [451 Oct. 17, 1972 United States Patent Peytavin [54] INTERMITTENTLY ACTING ROLLING 3,030,835 4/1962 Krause.....................72/2l4X MILL 2,680,391 6/1954 Kaiser............... ..........72/l89 [72] Inventor: Pierre Peytavin Neumy sur seine 2,703,999 3/1955 Gllle............................72/208 France Primary Examiner-Milton S. M ehr Attorney-Holcombe, Wetherill & Brisebois [73] Assignee: Societe anonyme dite: Vallourec [57] ABSTRACT lntermittently acting rolling mill comprising continu- (Usines a Tubes de Lorraine-Escaut et Vallourec Reunies), Bugeaud, Paris, France Dec. 29, 1969 ous rotary drive means, a roll cage which is reciprocated longitudinally of the work, means by which said work is intermittently rotated, and means for converting the continuous rotary movement of said drive means to reciprocating movement to drive said [22] Filed:

Appl. No.: 888,659

cage and intermittent rotary movement to turn said 90 Q7 21 b n m 2" Q LN m St Um an 55 [I work in synchronism with the movement of said cage.

[58] Field of Search........72/208, 209, 220, 214, 193,

8 Claims, 5 Drawing Figures [56] References Cited UNITED STATES PATENTS Wadleck..........

INTERMITTENTLY ACTING ROLLING MILL BACKGROUND OF THE INVENTION This invention relates to an intermittently driven rolling mill, and more particularly to a drive for periodically advancing the product to be rolled in a mill of this type.

intermittently driven rolling mills are rolling mills in which the cage supporting the rolls has an alternating movement with respectto the product being rolled. This alternating movement is synchronized with the rotation of the rolls, and means are provided for advancing the product being rolled between two successive rolling passes.

The present invention relates more particularly to the case in which the cage carrying the rolls is reciprocated with respect to the material being rolled. In this case, the product being rolled must be axially advanced between successive passes so that it is progressively gripped between the rolls which act thereupon, and may also have to rotate about its own axis.

Such intermittently driven rolling mills are a recent development which make it possible to roll material at relatively high speeds but require the advancement of the material being rolled during a relatively short period of time which must be precisely controlled.

SUMMARY OF THE INVENTION The present invention relates to a device which meets these requirements by using a particularly simple and sturdy mechanism.

In the description which follows a tube rolling machine will be specifically described, but the device according to the invention may also be used for rolling other types of material.

The object of the present invention is to provide a new article of manufacture which consists of an intermittently driven rolling mill comprising a device for rotating the product being rolled. This mill comprises a shaft continuously rotated in synchronism with the oscillation of the cage and which is connected to means which transform this continuous rotary movement into an intermittent rotary movement which is communicated to the product to be rolled. The machine is characterized by the fact that the continuous rotary movement is transmitted to as least one device for converting the continuous rotary motion into intermittent rotary motion which is positioned close to a clamp. Each clamp imparts intermittent rotation to the product being rolled. Each drive means drives only the clamp associated therewith.

In accordance with the invention the movement which produces the intermittent rotation of the product being rolled is thus transmitted in the form of continuous rotation to a point near the clamps which communicate intermittent rotation to the product being rolled. This results in a much more exact transmission of a successive rotation.

In order to transform the continuous rotation of the drive shaft into intermittent successive rotations, a suitable known device, such as a Ferguson transmission, is used. This consists of a particular type of worm screw and tangent wheel the teeth of which are so positioned that during the greater part of the rotation of the continuously driven drive shaft the shaft to be intermittently rotated is not driven, whereas over a relatively small angle (generally less than of the rotation of the continuously driven shaft, the intermittently actuated shaft is driven through a predetermined angle.

It is a further object of the present invention to provide a device for advancing the product being rolled step by step. This device is essentially characterized by the fact that it comprises a carriage mounted on a slideway extending longitudinally of the rolling mill. This carriage is driven by a variable speed drive such, for example, as screw and nut, and is continuously driven in synchronism with the oscillations of the cage of the rolling mill through a grooved shaft. The continuous rotation drives a cam which periodically swings a pressure member which axially displaces the product being rolled.

In a preferred embodiment of the invention the screw which drives the carriage is driven by a hydraulic motor which is supplied with pressure fluid by a variable output hydraulic pump carried by the device which drive the cage. The speed of rotation of the screw may be regulated by regulating the output of the hydraulic pump.

In this embodiment, it is particularly advantageous to also provide a source of hydraulic fluid under pressure connected to drive the hydraulic motor in reverse at high speed to provide a rapid reverse movement for the carriage.

In accordance with the preferred embodiment of the invention the two drive means which have just been described are combined in a single rolling mill. The carriage is driven directly from the continuously driven shaft which is used to produce the successive rotations of the product being rolled.

BRIEF DESCRIPTION OF THE DRAWING In order that the invention may be better understood one embodiment thereof will now be described purely by way of illustration and example, with reference to the accompanying drawings on which:

FIG. 1 is a schematic perspective view of an intermittently driven rolling mill according to the invention;

FIG. 2 is a schematic top plan view of the rolling mill shown in FIG. 1;

FIG. 3 is a sectional view taken through the carriage perpendicularly of the path of travel of the material being rolled; and

FIGS. 4 and 5 are sectional views: taken along the line IV-IV of FIG. 3 showing the positions of the pressure exerting arm at two different times.

The embodiment shown on the drawing is a device for rolling tubes in accordance with a known process in which the thickness of the tube wall is reduced by rolling it between two rolls while a mandrel having a diameter substantially equal to the internal diameter of the tube is maintained inside the tube in alignment with the rollers. This mandrel is carried by a rod which projects out of the rear end of the tube.

In accordance with this process, it is necessary to impart to the rod which supports the mandrel rotations corresponding to those which are imparted to the tube. On the other hand, the mandrel is not required to move axially.

FIG. 1 shows schematically an intermittently driven rolling mill comprising a roller cage 1 which is shown in broken lines because the details thereof are not essential to an understanding of the invention. This cage is reciprocated by two connecting rods 2 and 3 attached to cranks 4 and 5. The cranks are driven in synchronism in opposite directions through gearing 6 and 7 by a motor 8 schematically shown on FIG. 2.

FIGS. 1 and 2 also show schematically the two tube clamps 9 and 10 which hold the tubes in a conventional manner on opposite sides of the roller cage 1, together with the rod clamp 11 at the left end of the rolling mill. This rod clamp holds the mandrel carrying rod and imparts thereto successive rotations in synchronism with the rotations imparted to the tube clamps 9 and 10.

FIGS. 1 and 2 also show the shaft 12 which is driven continuously in synchronism with the rotation of the crank through the shafts 13 and 14 and gear boxes 15, 16 and 17, which have been schematically shown. The shaft 12 and the shaft 13 may, in an alternative embodiment, be the same. The shaft 12 is connected to three Ferguson gear boxes 18, 19 and 20 which, in response to each revolution of the shaft 12, impart a rotational movement through a given angle to the shafts 21, 22 and 23, which rotate the tube clamps 9 and and the rod clamp 11.

The gear boxes 18, 19 and are so arranged that during rotation through about 105, for example, they impart a rotation through 60 to the shafts 21, 22 and 23, whereas during the remaining portion of a complete revolution of the shaft 12 no rotation is imparted to the shafts 21, 22 and 23. It will be seen that in this manner a predetermined degree of rotation can be imparted to the tube clamps 9 and 10 and the rod clamp 11, which rotation takes place only during a period of time corresponding to a l05 rotation of the shaft 12.

Such gear boxes are sold by Ferguson under the name lntermittor.

FIGS. 1 and 2 also show the carriage 24 which is slidable on a slideway 25 carried by the framework of the rolling mill. This carriage is provided with a pressure-exerting arm 26 in the form of a fork which will be hereinafter described in greater detail.

A grooved rod 27 is rotationally driven by the shaft 13 through a transmission shaft 48 and turns in synchronism with the movements of the cage.

Alternatively, the shaft 12 itself may be partially grooved to cooperate with the carriage. In any case the transmission of continuous rotary movement for a substantial distance from the cranks 4 and 5 makes it easy to provide the necessary movement of the carriage.

A screw 28 axially displaces the carriage 24 by acting on a nut mounted inside that carriage. The screw 28 is driven by a hydraulic motor supplied through tubes 30 in a closed circuit including the variable output hydraulic pump 31, which is driven by the crank 5 which reciprocates the cage 1. It will be seen that, under these conditions, the speed of rotation of the screw 28 is proportional to the speed of rotation of the crank 5 and consequently to the frequency of reciprocation of the cage. The exact proportional relationship may be controlled by regulating the output of the pump 31. FIG. 1 schematically illustrates a source of hydraulic fluid under pressure 32 which is adapted to insure the rapid return of the carriage 24 when connected to supply a hydraulic motor 29 which operates in the reverse direction.

FIG. 3 shows on a larger scale a section taken through an embodiment of the carriage 24 which travels on the slideway 25 fixed to the framework of the rolling mill.

This figure shows the screw 28 which is engaged in a nut 33 fixed to the carriage so as to produce axial movement of the carriage.

FIG. 3 also shows the grooved rod 27 which drives a pinion 34 (shown in broken lines) the movement of which is transmitted to a bevel gear 35 through the transmission shaft 36 and bevel gears 37 and 38.

The gear 35 rotates a shaft 39 carrying an eccentric cam 40, one side of which may be seen on FIGS. 4 and 5.

The pressure-exerting arm 26 is pivotally attached at 42 to the carriage and actuated by cam 40 through a roller-carrying pin 41.

The lower branches of the pressure-exerting arm 26 act on the end of a movable sleeve 43 which is mounted to slide axially on the carriage. A return spring 44 constantly urges the sleeve 43 toward the right of the carriage.

Inside the sleeve 43 is a cylinder 45 mounted to turn about the axis of the sleeve 43. This cylinder is provided with a spring-biased stop 46 having an inclined surface 47 so that it is forced outwardly of the cylinder 45 when a tube is introduced into the cylinder from the left. When a tube is introduced from the right, as shown in broken lines on FIG. 4, the stop 46 prevents the tube from entering the cylinder 45. The operation of the device which has just been described will now be set forth.

As indicated above, the tube clamps 9 and 10 and the rod clamp 11 periodically rotate the tube and the mandrel carrying rod in synchronism with the reciprocating movement of the cage 1 of the rolling mill.

The tube clamps 9 and 10 are adapted to maintain the tube in its axial position when the tube is simply subjected to the strains which result from rolling, but when the cam 40 swings pressure-exerting arm 26 so as to displace the tube which is in contact with the stop 46 the tube clamps 9 and 10 permit this axial sliding of the tube without imposing any resistance thereto.

Since the cam 40 is rotatably driven by the grooved rod 27 attached to the crank 5 it will be appreciated that the movement of the pressure-exerting arm 26 is synchronized with the reciprocations of the cage 1 of the rolling mill.

On the contrary, the speed of rotation of the threaded rod 28 may be regulated at will so long as it remains proportional to the speed of the crank 5. The specific proportional relationship may be selected at will depending upon the extent of the axial advance which is desired.

The position of the elements shown on FIG. 4 corresponds to the moment at which a tube has just been axially advanced.

At this instant the cam 40 continues to rotate and progressively releases the pressure-exerting arm, the lower end of which is then free to move to the left. Simultaneously the screw 28 drives the carriage toward the right so as to compress the spring 44 since the cylinder 45 bears through the stop 46, on the end of the tube being rolled.

While the cam 40 is turning through a complete revolution the screw 28 displaces the carriage toward the right by a distance corresponding to the axial bite of the rollers, so that when the cam returns to the position shown in FIG. 5, it swings the pressure-exerting arm 26, the arms of which drive the sleeve 43, as well as the tube, toward the right.

FIG. 4 shows the position of the different elements at the moment at which the cam 40 has permitted the pressure exerting arm 26 to swing. It will then be returned to the position of FIG. 5 thus urging the tube to the right.

It will thus be seen that the axial displacement of the tube is entirely dependent upon the speed of rotation of the screw 28, since the movement of the pressure exerting arm 26 always has a constant amplitude. The pressure exerting arm 26 moves the cylinder and tube only to the extent that, between two bites, the carriage has been displaced to the right by the screw 28.

The invention accordingly makes it possible to advance the product being rolled in the required manner in a particularly simple and accurate way.

It will of course be appreciated that this embodiment has been described purely by way of example and may be modified as to detail without thereby departing from the basic principles of the invention, as defined by the following claims.

Iclaim:

1. Intermittently acting rolling mill comprising a reciprocating roller cage, drive means for continuously rotating in a single direction a drive member, which member is connected to drive said roller cage through means for converting the continuous rotary motion of said drive member to reciprocating movement by said cage, shaft means substantially parallel to the direction of reciprocation of said cage and connected to be continuously driven in synchronism with said drive member, at least one rotatable clamp for gripping a product being rolled in said roller cage, a device through which said at least one clamp is driven from said shaft means, which device converts the continuous rotation of said shaft means to intermittent rotation by said at least one clamp in synchronism with the reciprocating movement of said cage, a carriage for supporting said product, means for continuously driving said carriage in said direction of reciprocation,

oscillating means mounted on said carriage for intermittently advancing said product in the direction of reciprocation of said cage, and. means for converting continuous rotary motion to oscillating motion which connects said shaft means to drive said oscillating means and causes said oscillating means to oscillate in synchornism with the reciprocating movement of said cage.

2. Rolling mill as claimed in claim 1 in which said at least one clamp is stationary and permit axial sliding therein of the product to be rolled.

3. Rolling mill as claimed in claim 1 in which the means for converting continuous rotation to intermittent rotation comprises a worm and tangent wheel transmission of the Ferguson type.

4. Rolling mill is claimed in claim 1 in which the means for driving said carriage is a threaded rod substantially parallel to the direction of reciprocation of said cage and connected to be continuously rotated in s nchronism with said drive member.

y Rolling mill is claimed in claim 4 in which said threaded rod is driven by a hydraulic motor driven by a variable output hydraulic pump.

6. Rolling mill as claimed in claim 5 in which said means for converting continuous rotary motion to oscillating motion comprises a cam rotatably mounted on said carriage and in which said oscillating means is a pivotally mounted arm likewise mounted on said carriage and actuated by said cam to periodically advance the product being rolled, said continuously rotating shaft being connected to rotate said cam.

7. Rolling mill as claimed in claim 6 in which said carriage comprises a sleeve mounted to slide along the path of travel of the product to be rolled, in alignment with the roller cage which act on said product, spring means biassing said sleeve toward said cage and a cylinder coaxially and rotatably mounted in said sleeve, said cylinder being provided with a resiliently mounted stop which permits the product to be rolled to pass through said cylinder in one direction, but prevents its passage in the other direction.

8. Rolling mill as claimed in claim 5 comprising a source of pressure fluid and means for connecting said source to said hydraulic motor to drive it in a reverse direction.

UNITED STATES PATENT OFFICE CERTIFICATE OF' CORRECTION Patent No. 3 69-8 225 Dated October 17 1972 PIERRE PEYTAVIN Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[30] Foreign Application Priority Data Dec. 31, 1968 France PV 182,8 4

Signed and sealed this 13th day of February 1973.

(SEAL) Attest:

EDWARD M. FLETCHLR ,JR.

ROBERT GOTTSCHALK Attostlng Officer Commissioner of Patents FORM PO-l050 (IO-69) USCOMM-DC 60376-P69 u.s. GOVERNMENT PRINTING OFFICE 1 I989 O36G-334 

1. Intermittently acting rolling mill comprising a reciprocating roller cage, drive means for continuously rotating in a single direction a drive member, which member is connected to drive said roller cage through means for converting the continuous rotary motion of said drive member to reciprocating movement by said cage, shaft means substantially parallel to the direction of reciprocation of said cage and connected to be continuously driven in synchronism with said drive member, at least one rotatable clamp for gripping a product being rolled in said roller cage, a device through which said at least one clamp is driven from said shaft means, which device converts the continuous rotation of said shaft means to intermittent rotation by said at least one clamp in synchronism with the reciprocating movement of said cage, a carriage for supporting said prOduct, means for continuously driving said carriage in said direction of reciprocation, oscillating means mounted on said carriage for intermittently advancing said product in the direction of reciprocation of said cage, and means for converting continuous rotary motion to oscillating motion which connects said shaft means to drive said oscillating means and causes said oscillating means to oscillate in synchornism with the reciprocating movement of said cage.
 2. Rolling mill as claimed in claim 1 in which said at least one clamp is stationary and permit axial sliding therein of the product to be rolled.
 3. Rolling mill as claimed in claim 1 in which the means for converting continuous rotation to intermittent rotation comprises a worm and tangent wheel transmission of the Ferguson type.
 4. Rolling mill is claimed in claim 1 in which the means for driving said carriage is a threaded rod substantially parallel to the direction of reciprocation of said cage and connected to be continuously rotated in synchronism with said drive member.
 5. Rolling mill is claimed in claim 4 in which said threaded rod is driven by a hydraulic motor driven by a variable output hydraulic pump.
 6. Rolling mill as claimed in claim 5 in which said means for converting continuous rotary motion to oscillating motion comprises a cam rotatably mounted on said carriage and in which said oscillating means is a pivotally mounted arm likewise mounted on said carriage and actuated by said cam to periodically advance the product being rolled, said continuously rotating shaft being connected to rotate said cam.
 7. Rolling mill as claimed in claim 6 in which said carriage comprises a sleeve mounted to slide along the path of travel of the product to be rolled, in alignment with the roller cage which act on said product, spring means biassing said sleeve toward said cage and a cylinder coaxially and rotatably mounted in said sleeve, said cylinder being provided with a resiliently mounted stop which permits the product to be rolled to pass through said cylinder in one direction, but prevents its passage in the other direction.
 8. Rolling mill as claimed in claim 5 comprising a source of pressure fluid and means for connecting said source to said hydraulic motor to drive it in a reverse direction. 